One example of such a screen wiper mechanism, being especially of the type giving non-circular wiping, is described and shown in French published patent specification No. FR 1 546 319A. An improved articulating device for such a mechanism is the subject of French patent application No. 93 06724 filed on Jun. 4, 1993. In that improvement, the screen wiper mechanism is of the type which has an articulating device in which the connecting rod is coupled to the crank by means of a rotary pin. This pin has a head, a first cylindrical shank portion, and a second cylindrical shank portion of smaller diameter than the first shank portion. The head and the two shank portions are coaxial with each other, and the pin is of the type in which the first shank portion extends through a sleeve which is located within the connecting rod, while the second shank portion extends through a reinforcing element carried by the crank. The connecting rod carries at least one friction ring, and this ring, or at least one of these rings, is held against rotation with respect to the connecting rod.
In that arrangement, the friction rings, which are made of a suitable friction material in order to ensure their satisfactory operation, have to be gripped axially against the surfaces in facing relationship with them.
Given manufacturing tolerances in the various components of the articulating device, and in particular manufacturing tolerances of the pivot pin and of the opposed recesses which are formed in the opposed lateral faces of the connecting rod, it is found that proper axial gripping of the friction rings is not necessarily achieved, or may not be achieved to a sufficiently great extent, after assembly of the articulating device. In this connection, the assembly operation includes an operation to fasten the crank in position against axial movement with respect to the connecting rod; and this is achieved by, for example, a pressing operation which deforms the material of the pivot pin so as to form a second head at the free end of the latter, in the manner of a rivet.